refactor(language): centralize liveOrBetaStagesCount logic

Move liveOrBetaStagesCount getter to the Language model and update
templates and components to use this centralized property. Remove
duplicate stagesCount logic from TrackCard component.

Fix LeaderboardPage EntriesTable to use correct language argument.

These changes improve data consistency by deriving stage counts in one
place and simplify component code.

Author: rohitpaulk

app/components/leaderboard-page/entries-table.hbs

@@ -3,7 +3,7 @@
     <div>
       <table class="min-w-full bg-white">
         <thead>
-          <LeaderboardPage::EntriesTable::HeaderRow @language={{this.language}} />
+          <LeaderboardPage::EntriesTable::HeaderRow @language={{@language}} />
         </thead>
         <tbody>
           {{#each this.sortedTopEntries as |entry index|}}

app/components/tracks-page/track-card/index.hbs

@@ -28,11 +28,11 @@
   {{! Footer }}
   <div class="flex items-center justify-between">
     {{#if this.currentUserHasStartedTrack}}
-      <TracksPage::TrackCard::ProgressBar @completedStagesCount={{this.completedStagesCount}} @stagesCount={{this.liveOrBetaStagesCount}} />
+      <TracksPage::TrackCard::ProgressBar @completedStagesCount={{this.completedStagesCount}} @stagesCount={{@language.liveOrBetaStagesCount}} />
     {{else}}
       <div class="flex items-center">
         {{svg-jar "academic-cap" class="w-4 mr-1 fill-current text-gray-400 dark:text-gray-600"}}
-        <span class="text-xs text-gray-500">{{this.liveOrBetaStagesCount}} stages</span>
+        <span class="text-xs text-gray-500">{{@language.liveOrBetaStagesCount}} stages</span>
       </div>
     {{/if}}
 

app/components/tracks-page/track-card/index.ts

@@ -39,16 +39,6 @@ export default class TrackCard extends Component<Signature> {
     }
   }
 
-  get stagesCount() {
-    return this.store
-      .peekAll('course')
-      .rejectBy('releaseStatusIsAlpha')
-      .rejectBy('releaseStatusIsDeprecated')
-      .filter((course) => course.betaOrLiveLanguages.includes(this.args.language))
-      .mapBy('stages.length')
-      .reduce((a, b) => a + b, 0);
-  }
-
   @action
   async navigateToTrack() {
     await this.router.transitionTo('track', this.args.language.slug);

app/models/language.ts

@@ -152,6 +152,15 @@ export default class LanguageModel extends Model {
     return this.slug === 'go';
   }
 
+  get liveOrBetaStagesCount() {
+    return this.store
+      .peekAll('course')
+      .filter((course) => course.releaseStatusIsLive || course.releaseStatusIsBeta)
+      .filter((course) => course.betaOrLiveLanguages.includes(this))
+      .map((course) => course.stages.length)
+      .reduce((a, b) => a + b, 0);
+  }
+
   get sortPositionForTrack() {
     return [
       // Popular tracks, sorted by usage
@@ -164,15 +173,6 @@ export default class LanguageModel extends Model {
     ].join('');
   }
 
-  get liveOrBetaStagesCount() {
-    return this.store
-      .peekAll('course')
-      .filter((course) => course.releaseStatusIsLive || course.releaseStatusIsBeta)
-      .filter((course) => course.betaOrLiveLanguages.includes(this))
-      .map((course) => course.stages.length)
-      .reduce((a, b) => a + b, 0);
-  }
-
   get tealLogoUrl() {
     return {
       c: tealLogoC,